CHAPTER 2. CALIBRATION AND REPAIR SUPPORT

TB 750-25

CHAPTER 2

CALIBRATION AND REPAIR SUPPORT

2-1. General. This chapter provides information concerning the traceability of

measurements and general procedures concerning TMDE C&RS.

2-2. Traceability of Measurements

a. The DA TMDE C&RS program assures that measurements are traceable to the

national standards held by the National Institute of Standards and Technology (NIST),

the U. S. Naval Observatory (for time and frequency measurement standards), and

consensus standards. Measurements are traceable using standards whose values have

known relationships to the national standards. These known relationships can be

achieved by an unbroken chain of comparison with higher level standards, the use of

physical constants and construction, derivation from other basic standards, ratio

measurements, or combinations of the above. Traceability of measurement accuracy

may be provided by secondary transfer, secondary reference, or primary standards, or

even directly to NIST depending on the accuracy requirements of the owner/user. The

U. S. Army Primary Standards Laboratory (USAPSL) and TMDE support activities (TSA)

have been established worldwide to provide C&RS for U. S. Army TMDE, and in doing

so ensures traceability of measurements.

b. The U. S. Army Primary Standards Laboratory (USAPSL), located at Redstone

Arsenal, AL, provides the highest level of measurement support in the Army. TMDE

requiring this level of support is identified as primary "P" level in TB 43-180. This level

of support is generally limited to selected calibration standards at lower level

calibration facilities but may also include customer TMDE that is beyond the support

capability of lower level TSA's. The USAPSL receives calibration service from the NIST for selected

U. S. Army primary reference standards. Utilizing a nucleus of the NIST calibration

standards, fundamental physical constants, NIST measurement assurance program and

measurement error analysis, the USAPSL maintains its measurement capability and

provides verification of the validity of its calibrations. The USAPSL provides C&RS for

selected calibration standards in area calibration laboratories (ACL) and for TMDE

which requires the USAPSL level of support. All standards requiring NIST support is

coordinated with the Commander, U. S. Army Aviation and Missile Command, ATTN:

AMSAM-TMD, Redstone Arsenal, AL 35898-5400.

2-3 TMDE Support

a. The TSA is a generic term used to identify TMDE support organizations

providing C&RS. It includes TMDE support centers (TSC), area calibration laboratories

(ACL), TMDE maintenance companies, and their subordinate organizational elements,

such as mobile area TMDE support teams (ATST).

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